fn main() {
    let mut s = "initContent".to_string();

    s.push_str("string");
    println!("{}", s);
    let mut s1 = String::from("foo");
    let s2 = "bar";
    s1.push('l');
    println!("{}", s1);
    s1.push_str(s2);
    println!("s2 is {}", s2);
    let mut s = String::from("lo");
    s.push('l');
    println!("{}", s);
    println!("{}", s1);
    let s1 = String::from("Hello, ");
    let s2 = String::from("world");
    let res = s1 + &s2;
    println!("{}", res);
    let s1 = String::from("tic");
    let s2 = String::from("tic");
    let s3 = String::from("tic");
    let s = format!("{}-{}-{}", s1, s2, s3);
    println!("{}", s);
    let hello = "Здравствуйте";
    let s = &hello[0..4];
    println!("{}", s);
    for (index, c) in hello.chars().enumerate() {
        println!("{},{}", c, index);
    }
}
